1. Field of the Invention
The invention relates generally to the performance of medical and surgical procedures, particularly with the assistance of an imaging system for correlating the position of medical instruments with scanned images of the body. More particularly, the invention relates to the transfer of stored initialization information from the medical instruments to the imaging system so that the imaging system may be able to configure itself according to the particular type of attached medical instrument.
Determining the precise location of a medical instrument relative to a treatment region is critical in many surgical procedures. Unfortunately, locating the instrument relative to the treatment region can often be difficult, particularly when the treatment region is within the patient and out of the surgeon's view. To assist in locating both the treatment region and the medical instrument, a variety of imaging systems have been proposed including computerized tomographic (CT) scans, magnetic resonance imaging (MRI) scanning, positron emission tomographic (PET) scanning, and the like. Although generally successful in producing detailed images of the body, one difficulty experienced with such systems is the need to correlate the position of a therapeutic or a surgical instrument during treatment with the produced diagnostic image of the treatment region so that the surgeon can correctly position the instrument at the treatment region.
One promising imaging system for detecting the position of the medical instrument relative to a diagnostic image of the treatment region is described in U.S. Pat. No. 5,383,454, the disclosure of which is herein incorporated by reference. Briefly, such a system provides a plurality of discrete energy-emitting elements on the medical instrument which are detected by a receiver near the operative site. With the use of a computer, the detected signals are used to determine the location of the medical instrument relative to the receiver. The patient's position is initialized and/or the patient is provided with a series of energy-emitting devices so that the location of the patient relative to the receiver is known. The computer is then able to track the location of the medical instrument relative to the patient in real-time. Such information can then be correlated with previously produced images of the patient's body which are produced on a screen. In this way, as the surgeon moves the instrument to the treatment region, an image can be produced on the screen showing a marker indicative of the instrument position relative to the previously produced image of the body (which corresponds to the actual position of the treatment region relative to the medical instrument).
One particular advantage of such a system is that it may be configured to track a wide variety of medical instruments simply by reinitializing the imaging system each time a new instrument is attached so that the system will be properly configured according to the attached instrument. Such initialization information can include, for example, the number of energy-emitting elements on the instrument, the location of the energy-emitting elements relative to a work portion of the medical instrument, and the like. Usually, such information is manually entered into the computer, such as by use of a keyboard or the like. However, manually initializing the imaging system in such a manner suffers from a number of serious drawbacks. For example, the initialization information may be improperly input into the system which may result in the improper tracking of the medical instrument. Another drawback is that the medical instrument may be removed from the system following initialization and replaced with another instrument. If the system is not reinitialized, improper tracking of the new instrument may result. In a further drawback, the manual entry of such initialization information is time-consuming and nay increase the length of the medical procedure.
Hence, for these and other reasons it would be desirable to provide an improved imaging system that would overcome or greatly reduce all or at least some of these drawbacks. In particular, it would be desirable to provide improvements in the initialization of the imaging system so that initialization information can correctly and efficiently be input into the system. Such improvements should also provide improved safety by ensuring that the imaging system is properly initialized upon connection of each type of medical instrument.
2. Brief Description of the Background Art
As previously described, U.S. Pat. No. 5,383,454 discloses a system for indicating the position of a surgical probe on a previously produced image of the patient's body.
Canadian Patent Application Serial No. 2003497 describes a system for visualizing an image of a hand held probe relative to previously produced images of the patient's body. The complete disclosure of this application is incorporated herein by reference.
U.S. Pat. No. 4,672,306 describes an electronic probe assembly that provides previously recorded data as to probe identification and optimum compensation tuning of the probe to a connected "intelligent" test and measurement device.
Romilly Bowden, Smart instruments to get smarter, Process Engineering, November 1992, p. 41, describes a hand held communicator for ensuring compatibility between different manufacturer's instruments.
E. Lee Garelick, Why calibrate "smart" instruments?, Intech, February 1990, pp. 26-27, describes the calibration of "smart" instruments.